This invention relates to a coating composition and in particular to a coating composition that cures rapidly at ambient temperatures to a hard, glossy, durable, and weatherable finish. Acrylic alkyd coating compositions are widely used for painting or refinishing automobiles and trucks. One particularly high quality acrylic alkyd composition of this type is described in Miller and Walus U.S. Pat. No. 3,585,160, issued June 15, 1971. This enamel has an excellent adherence to primed, uncoated, enamel coated or lacquer coated metal substrates and dries to a glossy, smooth and durable finish. However, this composition does not cure rapidly at ambient temperature to a hard, tough, durable finish but may take up to a week of cure to reach maximum properties. Another useful acrylic alkyd coating composition containing a polyisocyanate is shown in Miller U.S. Pat. No. 3,844,993 issued Oct. 29, 1974 that does cure rapidly to form a useful finish. Current requirements are for improved durable and weatherable composition that retain the rapid cure characteristics of the above composition.
The improved composition of this invention has all of the desirable characteristics of these prior art compositions along with improved durability and weatherability.